When Facebook and Twitter moved quickly this week to limit the spread of an unverified political story published by the conservative-leaning New York Post, it led to predictable cries of censorship from the right. But it also illustrated the slippery hold even the largest tech companies have on the flow of information. While Facebook and Twitter have often been slow to combat apparent misinformation ... their response in this case shows how quickly they can move when they want to. For the first time in recent memory, the two social media platforms enforced rules against misinformation on a story from a mainstream media publication. The story in question, which has not been confirmed by other publications, cited unverified emails from Democratic presidential nominee Joe Biden's son that were reportedly discovered by President Donald Trump's allies. Facebook used the possibility of false information as the reason to limit the article's reach, which means its algorithm shows it to fewer people, much the way you might not see as many posts from friends you don't interact with often. Twitter, meanwhile, blocked users from tweeting out the link to the story and from sending it in private messages. Though they acted quickly, both companies stumbled on communicating their decision to the public. In part because of this, and in part by the mere act of trying to limit the story, the tech platforms soon became the story.